胺型键合固定相分离碱性物质的影响因素考察

 以某些碱性物质为探测溶质 ,中性物质乙苯为参照溶质 ,详尽考察了检测温度、缓冲液中阳离子浓度、流动相的流速分别在流动相的 pH值为 3 0和 7 0时对胺型键合固定相分离碱性物质的影响。研究结果表明 ,随着温度的升高 ,碱性物质的保留时间先下降较快 ,然后趋于平缓 ,而柱效和峰形分别得到了提高和改善 ;缓冲液中阳离子浓度对碱性物质的保留行为有较大的影响 ;碱性物质的最佳流速较中性物质小。由于胺型键合固定相中的疏水烷基链中引入了极性官能团氨基 ,因此碱性物质在该固定相上的行为比在传统的固定相上更为复杂。

Study of the Separation Factors of Basic Compounds in HPLC Using a Reversed-Phase Amino-Type Column

The chromatographic behaviors of some basic probes and a neutral reference compound were investigated as functions of temperature, buffer cation strength and flow rate using a novel reversed phase amino type column at both pH 3 0 and pH 7 0. The results showed that the retention of basic compounds declined steeply at first, but then slowly when temperature increased continually at pH 3 0 while decreased slowly in the whole range of temperature at pH 7 0. The column efficiency increased and the peak shape improved with increased temperature. The buffer cation strength has a strong effect on the retention of bases. The optimum flow rate for the highest efficiency is generally lower for basic compounds than neutral compounds, and due to the steepness of the van Deemter curves obtained , high flow rates appear to be particularly detrimental in the chromatography of basic compounds. All the results indicated that the retention mechanism was more complex for the analysis of bases on amino type columns than on traditional reversed phase columns because of the existence of amino group in the alkyl group of amino type columns.